WASHINGTON  Deer in Montgomery County, Md., enjoy many of the conveniences of modern suburban life: abundant food, few predators, a little room to spread out. Oh yes, and contraception.

Since the mid-1990s, deer on the campus of the National Institute of Standards and Technology in Gaithersburg have been able to rut without regret, thanks to a contraceptive program administered by the Humane Society of the United States.

Deer living on federal property in White Oak, in eastern Montgomery County, are being injected with a different contraceptive that will prevent pregnancy by keeping them from going into heat. This scientific advance  the no-sex deer  is the result of research by the Agriculture Department's National Wildlife Research Center.

Tagged for monitoring

The center this month is capturing 40 to 60 does at White Oak, half of which will be injected with the no-sex contraceptive. The other half will serve as a control group. All will be tagged and fitted with radio collars for monitoring.

The goal is a one-shot deer contraceptive that would offer those in charge of managing deer populations a realistic alternative to killing.

Deer populations have boomed in the past century, causing communities nationwide to find ways to shrink the size of herds. In most cases, officials have used hunters or sharpshooters to cull deer, but animal-rights activists and others have called for the development of a deer contraceptive.

"It's kind of the Holy Grail of (deer contraception): to come up with something that you could inject once and have it work for five years or so," said Michael Newman, spokesman for the National Institute of Standards and Technology.

That's the goal of the White Oak trial. The contraceptive works by inducing antibodies to attack a hormone necessary for reproduction, effectively shutting down the animals' reproductive systems.

In tests at Pennsylvania State University, researchers have found that vaccinated does do not go into estrus, or heat, and that bucks don't rut.

"We believe it's effective for two to three years," said Kathleen Fagerstone, acting director of the center.

The technology at the institute involves the immune system in a different way. That vaccine uses a protein from pigs to generate antibodies that render eggs of female deer impervious to sperm. The vaccine, however, requires annual booster shots.

Canadian biologists have developed a one-shot vaccine using similar technology, but their product, known as SpayVac, does not eliminate heat and rutting. "It's really quite elegant," said Mark Fraker, president of SpayVac-for-Wildlife. "The animals maintain their normal behavior; they just don't get pregnant."

None of these products has received approval from the Food and Drug Administration, so their use is limited to experimental trials. Deer are tagged with a warning that they are not to be consumed by humans.

Program under way

A contraceptive program has been under way at Fire Island, N.Y., since the early 1990s. Since then, perhaps a half-dozen other communities have hosted contraceptive trials, but the method requires money and patience. Anthony DeNicola, a biologist who runs a nonprofit wildlife-management firm, White Buffalo, said the best solution might be a combination of lethal culling and contraception. He advises communities to tag, mark and vaccinate the most approachable deer in a target population "and kill all the others."

Contraception is expensive, largely because of the cost of capturing deer. SpayVac's Fraker estimates that a contraception program can cost $300 to $500 per deer; inviting hunters in to use lethal means often can be free.

The institute's program has reduced the size of the herd on the institute's 578-acre campus from a late-1990s peak of 320 to 200, Newman said.

The no-sex contraceptive might have an additional advantage if the goal is to prevent deer from becoming a nuisance or a threat to humans. Eliminating rutting, which can make deer oblivious to such things as vehicles in their surroundings, could cut down on the number of collisions between deer and cars  one of the main reasons communities want to reduce their deer populations. At the same time, scientists have no idea what other ramifications might ensue from suppressing the urge to mate.